Balanced slide-valve



' R. HIATT.

.BALANCED SLIDE VALVE. APPLICATION FILED APR. 9. 1920.

WM a

UNITED STATES PATENT OFFICE.

RAY HIATT, OF ESBON, KANSAS.

.'BALANCED SLIDE-VALVE.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed April 9, 1920. Serial No. 372,539.

gines; and it consists in the novel construction and combination of the parts hereinafter fully described and claimed whereby the valve balance-plate will over-run its seat at short strokes and will substantially balance the valve at all strokes.

In the drawings, Figure 1 is a longitudinal section through a balanced slide-valve constructed according to this invention. F ig. 2 is a plan view of the balance-plate.

The engine cylinder 2 has steam ports 3, and an exhaust portt. The steam-chest 5 has a valve seat 6, and 7 is the slide-valve. All of these parts are of any approved construction. The slide-valve has a projection or piston 8 on its back which works in a cylinder or cover 9 formed on the balance-plate 10, and these parts are kept steam-tight in any approved way. The balance-plate 10 slides against a seat 12 on the cover 111 of the steam-chest. lVhen the slide-valve is working at short stroke, the main portion of the balance-plate does not over-ride the ends of its seat 12, and in order to prevent the formation of shoulders on the seat 12, the balanceplate is provided with extensions 15 at its ends having cross-grooves 16 formed in them. These grooves are always in free communication with the steam space of the steamchest, and they form relatively narrow contact faces 18 at the ends of the balance-plate which over-run the ends of the seat 12. The seat 12 and the extensions 15 are proportioned so that the extensions 15 over-ride the ends of the seat 12 at all strokes of the valve. This construction permits the slide-valve t0 remain substantially balanced when working at all strokes, as the faces 18 are relatively narrow. The narrow faces 18 and grooves 16 do not materially affect the balance of the valve, and they have no effect on the distribution of the steam. They are provided for the purpose of preventing the plate 10 from wearing shoulders on the seat 12 when the valve is working at short stroke and the main portion of the plate 10 does not pass beyond the ends of the seat 12.

lVhat I claim is:

In a balanced slide valve, a steam-chest provided with seats arranged parallel to each other, a slide-valve working against one seat, and a balance-plate working against the other seat and operatively connected with the slide-valve, said balance-plate having eX- tensions at its ends provided with crossgrooves which constantly communicate with the steam space of the steam-chest and which form relatively narrow contact faces at the ends of the balance-plate, said faces being arranged to over-ride the ends of the seat against which they bear at all strokes of the valve, thereby preventing the formation of shoulders on the'said seat.

In testimony whereof I have aliXed my signature.

RAY I-IIATT. 

